Information on towels here it says the same as me 'DO NOT USE FABRIC CONDITIONER'
http://www.richardhaworth.co.uk/bath-linen-guide
To get 'fluffy' towels you must have high quality towels in the first place a cheap towel will never fluff up.
Towel quality is determined by the weight in Gram per Square Meter GSM
For a good quality towel you need at least 700 GSM , the best are 900 to 950 GSM.
Cheap towels , ok for a gym towel, are 300 to 400 GSM .
Tea towels are only 150 to 200 GSM
Finally only buy 100% cotton towels, they can absorb 25 x their own weight in water !